<div class="listItem">
  <div class="actionContainer">
    <button mat-raised-button (click)="addMarker()">添加marker</button>
    <button mat-raised-button (click)="addPolygon()">添加polygon</button>
    <input matInput placeholder="choice color" type="color" value="#FF0000" (input)="choiceColor($event)" />
    <input type="file" (change)="choiceFile($event)" accept=".shp" />
  </div>
  <cdk-virtual-scroll-viewport itemSize="20" class="example-viewport">
    <div *cdkVirtualFor="let shoe of posArr; index as i;" class="example-item" (click)="choice(shoe)">
      <mat-checkbox [(ngModel)]="shoe.completed" [color]="shoe.color">
        第{{shoe.id || i+1}}个点
      </mat-checkbox>
    </div>
  </cdk-virtual-scroll-viewport>
</div>